Thanks Chris.  I tried editing the run_mri_reface_docker.sh to add "--platform linux/amd64" to the docker run command.  This eliminates the warning since I'm specifying a platform, but that didn't resolve the error about mclmcr initialization, which I assume is because that isn't the actual hardware I'm using. 

If I update the script to specify "--platform linux/arm64/v8" I get an error that's essentially indicating an image for mri_reface with that platform doesn't exist on dockerhub. 

After digging into this a little, I read that you should be able to specify that you want to provide a Mac release tailored for Apple silicon using BuildX when you create your Docker image.  E.g. "docker buildx build --platform linux/arm64 -t my-image:latest".  I'd be happy to test this out for you if that's something you can try. 

Also, I was able to fix the "chmod: Invalid file mode: =777" error I was getting by editing your .sh file to remove the space before the = in that line.  I.e. "chmod =777 -R $tmpdir" --> "chmod=777 -R $tmpdir".  I guess Macs are fussier about this syntax than PCs.